Embers

Glowing coals are lit. Tapping a coal flips it and the coals directly above, below, left and right of it: lit goes out, out lights up.

Every board can be solved. Easy hides 3 taps, medium 6, hard 10, though you may find a shorter way. Fewer moves is better.

Your best move count for each level is kept in this browser only. Nothing you do here is sent anywhere.